Overexpression of Growth Differentiation Factor 15 in Glioblastoma Stem Cells Promotes Their Radioresistance

GSCs play an important role in GBM recurrence. Understanding the resistance mechanisms in these cells is therefore crucial for radiation therapy optimization. In this study, using patient-derived GSCs, we demonstrate that GDF15, a cytokine belonging to the TGF-β superfamily, is regulated by irradiation (IR) and the transcription factor WWTR1/TAZ. Blocking WWTR1/TAZ using specific siRNAs significantly reduces GDF15 basal expression and reverses the upregulation of this cytokine induced by IR. Furthermore, we demonstrate that GDF15 plays an important role in GSC radioresistance. Targeting GDF15 expression by siRNA in GSCs expressing high levels of GDF15 sensitizes the cells to IR. In addition, we also found that GDF15 expression is critical for GSC spheroid formation, as GDF15 knockdown significantly reduces the number of GSC neurospheres. This study suggests that GDF15 targeting in combination with radiotherapy may be a feasible approach in patients with GBM.

Evaluation of in vitro intrinsic radiosensitivity and characterization of five canine high-grade glioma cell lines

Glioma is the most common primary brain tumor in dogs and predominantly affects brachycephalic breeds. Diagnosis relies on CT or MRI imaging, and the proposed treatments include surgical resection, chemotherapy, and radiotherapy depending on the tumor's location. Canine glioma from domestic dogs could be used as a more powerful model to study radiotherapy for human glioma than the murine model. Indeed, (i) contrary to mice, immunocompetent dogs develop spontaneous glioma, (ii) the canine brain structure is closer to human than mice, and (iii) domestic dogs are exposed to the same environmental factors than humans. Moreover, imaging techniques and radiation therapy used in human medicine can be applied to dogs, facilitating the direct transposition of results. The objective of this study is to fully characterize 5 canine glioma cell lines and to evaluate their intrinsic radiosensitivity. Canine cell lines present numerous analogies between the data obtained during this study on different glioma cell lines in dogs. Cell morphology is identical, such as doubling time, clonality test and karyotype. Immunohistochemical study of surface proteins, directly on cell lines and after stereotaxic injection in mice also reveals close similarity. Radiosensitivity profile of canine glial cells present high profile of radioresistance.

The STEMRI trial: Magnetic resonance spectroscopy imaging can define tumor areas enriched in glioblastoma stem-like cells

Despite maximally safe resection of the magnetic resonance imaging (MRI)-defined contrast-enhanced (CE) central tumor area and chemoradiotherapy, most patients with glioblastoma (GBM) relapse within a year in peritumoral FLAIR regions. Magnetic resonance spectroscopy imaging (MRSI) can discriminate metabolic tumor areas with higher recurrence potential as CNI+ regions (choline/N-acetyl-aspartate index >2) can predict relapse sites. As relapses are mainly imputed to glioblastoma stem-like cells (GSCs), CNI+ areas might be GSC enriched. In this prospective trial, 16 patients with GBM underwent MRSI/MRI before surgery/chemoradiotherapy to investigate GSC content in CNI-/+ biopsies from CE/FLAIR. Biopsy and derived-GSC characterization revealed a FLAIR/CNI+ sample enrichment in GSC and in gene signatures related to stemness, DNA repair, adhesion/migration, and mitochondrial bioenergetics. FLAIR/CNI+ samples generate GSC-enriched neurospheres faster than FLAIR/CNI-. Parameters assessing biopsy GSC content and time-to-neurosphere formation in FLAIR/CNI+ were associated with worse patient outcome. Preoperative MRI/MRSI would certainly allow better resection and targeting of FLAIR/CNI+ areas, as their GSC enrichment can predict worse outcomes.

First report of eprinomectin-resistant isolates of Haemonchus contortus in 5 dairy sheep farms from the Pyrénées Atlantiques département in France

Infection of sheep by gastrointestinal nematodes (GIN) in pastoral systems such as those found in the South Western area of France, the Pyrénées Atlantiques, is one of the main reasons for economic loss and degradation of their welfare. In the present study, the efficacy of eprinomectin (EPN) was monitored on farms from this area following suspicion of lack of anthelmintic efficacy. Suspicions were raised by veterinarians, based on clinical signs ranging from milk and body condition loss, to anaemia, and mortality. Resistance was evaluated according to the World Association for the Advancement for Veterinary Parasitology (WAAVP) guidelines using fecal egg count reduction tests reinforced by individual analysis of drug concentration in the serum of all treated ewes by high-performance liquid chromatography (HPLC). EPN was administered by subcutaneous (SC) and topical (T) route according to manufacturer's requirements, as well as by the oral route (O) with the topical solution according to off-labelled practices in the field. For the first time in France, the presence of resistant isolates of Haemonchus contortus to EPN was observed in 5 dairy sheep farms. The HPLC dosages showed exposure of worms to concentrations compatible with anthelmintic activity for animals treated by the SC and O routes. By contrast, they showed under exposure to the drug of most individuals treated by the T route. EPN is the only null milk withdrawal anthelmintic molecule currently available. The presence of resistant isolates of the pathogenic H. contortus to EPN in this important dairy region requires an urgent change in grazing, and sometimes production, systems.

Prevalence of illicit drugs use and association with in-hospital major adverse events in patients hospitalised for acute cardiac events: the ADDICT-ICCU Trial

Background

The prevalence and short-term cardiovascular consequences of illicit drug use in patients admitted to the intensive cardiac care unit (ICCU) for acute cardiovascular events are not well established.

Purpose

The Addiction in Intensive Cardiac Care Units (ADDICT-ICCU) study was designed to assess prospectively the prevalence of illicit drugs use, and their association with the occurrence of in-hospital major adverse events (MAEs) in consecutive patients admitted to ICCUs for acute cardiovascular events.

Methods

From 7 to 22 April 2021, screening for illicit drug was performed by systematic urinary testing in a prospective study including all consecutive patients admitted to ICCU in 39 centres throughout France. The primary outcome was the prevalence of the illicit drugs detected. The secondary clinical outcome was in-hospital Major Adverse cardiac Events (MAEs) defined by death, resuscitated cardiac arrest or cardiogenic shock.

Results

Among 1,499 consecutive patients screened (age 63.3±14.9 years, 69.6% male), 161 (10.7%) had a positive test for illicit drugs (cannabis: 9.1%, opioids: 2.1%, cocaine: 1.7%, amphetamines: 0.7%, 3,4-methylenedioxymethamphetamine: 0.6%). Patients who used illicit drugs were young (33.0% at age <40 vs. 5.9% at age ≥60 years), and more frequently male (11.9% vs. 8.1%, p<0.001). Self-reported current use was 56.5% in patients with a positive test. After a median duration of hospitalisation of five days, there were 61 in-hospital MAEs (4.1%).

The detection of illicit drugs was associated with a higher rate of MAEs after adjustment for known predictors of severity (OR=8.84; 95% CI: 4.68–16.7, p<0.001) or after using a propensity score adjustment (OR=5.81; 95% CI: 4.14–8.14, p<0.001). After adjustment for age and sex, detection of cannabis or cocaine was significantly associated with MAEs (OR=3.53; 95% CI: 1.25–9.95, p<0.001; OR=5.12; 95% CI: 1.48–17.2, p=0.004 respectively). Multiple drug detection (28% of positive patients) was associated with a higher incidence of MAEs than single drug detection.

Conclusions

The prevalence of illicit drugs use in patients hospitalised in the ICCUs for acute cardiovascular events was 10.7% and was under-reported. Illicit drugs detection was independently associated with a higher occurrence of in-hospital MAEs.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fondation Coeur et Recherche

Myocardial bridging is significantly associated with myocardial infarction with non-obstructive coronary arteries

Background

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a common disorder characterized by the presence of clinical criteria for acute myocardial infarction in the absence of obstructive coronary artery disease on angiography. We aim to investigate the relationship between myocardial bridging (MB) and MINOCA.

Methods

An observational retrospective study was conducted on 15,036 patients who had been referred for coronary angiography and who fulfilled the Fourth Universal Definition of Myocardial Infarction. The study population was divided into STEMI and non-STEMI patients, from which we defined two main groups: the MINOCA group and the coronary artery disease (CAD) group. Statistical analyses were carried out by using SPSS, version 20.

Results

The prevalence of angiographic MB among the groups was significantly greater in the MINOCA group (2.9% vs. 0.8%). MINOCA accounted for 14.5% of spontaneous myocardial infarction, and the clinical presentation was frequently NSTEMI rather than STEMI (84.3% vs. 15.7%). After adjusting for confounders, multivariate analyses showed a positive association between MB and MINOCA [OR=3.28, 95% CI (2.34; 4.61) p<0.001]. Cardiovascular risk factors were less common in the MINOCA population, which was younger and more often female.

Conclusion

MB is a risk factor for MINOCA. Because MB prevalence differed significantly between the controls (CAD group) and cases (MINOCA group), which were positively associated to MB, it seems likely that MB would be a potential cause of MINOCA. Investigations for MB in MINOCA cases and especially in NSTEMI patients seem necessary.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Rangueil Hospital

Glioblastoma Stem-like Cell Detection Using Perfusion and Diffusion MRI

Simple Summary

Glioblastoma stem-like cells (GSCs) are known to be aggressive and radio-resistant and proliferate heterogeneously in preferred environments. Additionally, quantitative diffusion and perfusion MRI biomarkers provide insight into the tissue micro-environment. This study assessed the sensitivity of these imaging biomarkers to GSCs in the hyperintensities-FLAIR region, where relapses may occur. A total of 16 patients underwent an MRI session and biopsies were extracted to study the GSCs. In vivo and in vitro biomarkers were compared and both Apparent Diffusion Coefficient (ADC) and relative Cerebral Blood Volume (rCBV) MRI metrics were found to be good predictors of GSCs presence and aggressiveness.

Abstract

Purpose: With current gold standard treatment, which associates maximum safe surgery and chemo-radiation, the large majority of glioblastoma patients relapse within a year in the peritumoral non contrast-enhanced region (NCE). A subpopulation of glioblastoma stem-like cells (GSC) are known to be particularly radio-resistant and aggressive, and are thus suspected to be the cause of these relapses. Previous studies have shown that their distribution is heterogeneous in the NCE compartment, but no study exists on the sensitivity of medical imaging for localizing these cells. In this work, we propose to study the magnetic resonance (MR) signature of these infiltrative cells. Methods: In the context of a clinical trial on 16 glioblastoma patients, relative Cerebral Blood Volume (rCBV) and Apparent Diffusion Coefficient (ADC) were measured in a preoperative diffusion and perfusion MRI examination. During surgery, two biopsies were extracted using image-guidance in the hyperintensities-FLAIR region. GSC subpopulation was quantified within the biopsies and then cultivated in selective conditions to determine their density and aggressiveness. Results: Low ADC was found to be a good predictor of the time to GSC neurospheres formation in vitro. In addition, GSCs were found in higher concentrations in areas with high rCBV. Conclusions: This study confirms that GSCs have a critical role for glioblastoma aggressiveness and supports the idea that peritumoral sites with low ADC or high rCBV should be preferably removed when possible during surgery and targeted by radiotherapy.

Assurer le contrôle qualité d'un essai clinique pendant la pandémie de COVID-19 : l'expérience de l'étude Inserm C20-15 DisCoVeRy en France

Introduction

Les mesures sanitaires mises en place pendant la pandémie, telles que la distanciation sociale et les confinements, ont profondément modifié les pratiques de recherche clinique en restreignant l'accès aux participants en raison des risques de contamination, et en limitant la disponibilité du personnel des sites en raison de la surcharge de travail. Dans le même temps, la demande de résultats issus des essais COVID-19 était urgente et soumise à la pression de la communauté scientifique, de la société civile et des médias. Ainsi, l'objectif de cette communication est de partager l'expérience de l'Inserm pour assurer le contrôle qualité d'un essai clinique dans ce contexte particulier.

Methodes

DisCoVeRy est une étude de phase III adaptative et randomisée qui visait, dans sa première phase, à évaluer la sécurité et l'efficacité de 4 stratégies thérapeutiques chez des patients adultes hospitalisés pour COVID-19 ayant un besoin de supplémentation en oxygène. Entre le 22 mars 2020 et le 20 janvier 2021, 1176 patients ont été inclus en France. Afin de garantir la qualité des données recueillies, le promoteur a dû s'adapter aux mesures sanitaires en vigueur et à leur impact sur l'activité de recherche clinique. Il s'agissait notamment : d'adapter les objectifs du Plan de Monitoring (vérification des données sources pour 100% des données critiques de tous les participants), d'impliquer les Direction de la Recherche et de l'Innovation (DRI) des hôpitaux participants, de solliciter un réseau d'assistants de recherche clinique (ARC) et des personnels Inserm.

Resultats

Au total, 91 ARCs ont été impliqués en France et ont effectué 834 visites de monitoring du 24 avril 2020 au 15 octobre 2021, donnant lieu à 539 rapports de monitoring. Parmi les 1176 patients inclus et randomisés, un consentement a été obtenu permettant l'analyse de toutes les données chez 1112 (94,6%), des données jusqu'à la levée de la sédation chez 23 (1,9%), des données jusqu'au retrait du consentement ou à la décision de l'investigateur principal chez 32 (2,7%). Neuf (0,8%) patients n'ont pu être analysés en l'absence de consentement conforme. Le contrôle de 100% des données critiques pour tous les patients inclus dans l'analyse a été réalisé, conformément au Plan de Monitoring. Les résultats de l'étude ont été publiés en mai et septembre 2021. Au regard de l'importance de rendre les résultats publics, ces premières publications ont été soumises sans que toutes les données critiques aient été contrôlées. Le monitoring du consentement, des critères de sélection et du critère d'évaluation principal avait été priorisé afin d'assurer la fiabilité des résultats sur ces éléments majeurs.

Conclusion

Malgré le démarrage contraint de l'étude avant la mise en place de l'équipe de monitoring, le rythme d'inclusion très élevé, et les contraintes majeures liées au contexte pandémique, l'ensemble des données critiques selon le Plan de Monitoring initial a été monitoré en seulement 18 mois. Ce résultat est notamment dû à la mobilisation de ressources en personnel considérables, dans un délai très court. Cependant, la mise en place d'une telle organisation souligne l'importance de disposer d'indicateurs faciles à consulter en temps réel pour aider au pilotage de l'étude et à la planification de l'utilisation de la base de données et de la publication des résultats.

Mots clés contrôle qualité ; monitoring ; consentement ; promotion

Déclaration de liens d'intérêts Les auteurs n'ont pas précisé leurs éventuels liens d'intérêts

The m6A RNA Demethylase ALKBH5 Promotes Radioresistance and Invasion Capability of Glioma Stem Cells

Simple Summary

Glioblastoma stem cells (GBMSCs), which are particularly radio-resistant and invasive, are responsible for the high recurrence of glioblastoma (GBM). Therefore, there is a real need for a better understanding of the mechanisms involved in these processes and to identify new factors that might be targeted to radiosensitize GBMSC and decrease their invasive capability. Here, we report that the m6A RNA demethylase ALKBH5, which is overexpressed in GBMSCs, promotes their radioresistance by controlling the homologous repair. ALKBH5 was also involved in GBMSC invasion. These data suggest that ALKBH5 inhibition might be a novel approach to radiosensitize GBMSCs and to overcome their invasiveness.

Abstract

Recurrence of GBM is thought to be due to GBMSCs, which are particularly chemo-radioresistant and characterized by a high capacity to invade normal brain. Evidence is emerging that modulation of m6A RNA methylation plays an important role in tumor progression. However, the impact of this mRNA modification in GBM is poorly studied. We used patient-derived GBMSCs to demonstrate that high expression of the RNA demethylase, ALKBH5, increases radioresistance by regulating homologous recombination (HR). In cells downregulated for ALKBH5, we observed a decrease in GBMSC survival after irradiation likely due to a defect in DNA-damage repair. Indeed, we observed a decrease in the expression of several genes involved in the HR, including CHK1 and RAD51, as well as a persistence of γ-H2AX staining after IR. We also demonstrated in this study that ALKBH5 contributes to the aggressiveness of GBM by favoring the invasion of GBMSCs. Indeed, GBMSCs deficient for ALKBH5 exhibited a significant reduced invasion capability relative to control cells. Our data suggest that ALKBH5 is an attractive therapeutic target to overcome radioresistance and invasiveness of GBMSCs.

Pharmacogenetic Study of Trabectedin-Induced Severe Hepatotoxicity in Patients with Advanced Soft Tissue Sarcoma

Hepatotoxicity is an important concern for nearly 40% of the patients treated with trabectedin for advanced soft tissue sarcoma (ASTS). The mechanisms underlying these liver damages have not yet been elucidated but they have been suggested to be related to the production of reactive metabolites. The aim of this pharmacogenetic study was to identify genetic variants of pharmacokinetic genes such as CYP450 and ABC drug transporters that could impair the trabectedin metabolism in hepatocytes. Sixty-three patients with ASTS from the TSAR clinical trial (NCT02672527) were genotyped by next-generation sequencing for 11 genes, and genotype-toxicity association analyses were performed with R package SNPassoc. Among the results, ABCC2 c.1249A allele (rs2273697) and ABCG2 intron variant c.-15994T (rs7699188) were associated with an increased risk of severe cytolysis, whereas ABCC2 c.3563A allele had a protective effect, as well as ABCB1 variants rs2032582 and rs1128503 (p-value < 0.05). Furthermore, CYP3A5*1 rs776746 (c.6986A > G) increased the risk of severe overall hepatotoxicity (p = 0.012, odds ratio (OR) = 5.75), suggesting the implication of metabolites in the hepatotoxicity. However, these results did not remain significant after multiple analysis correction. These findings need to be validated on larger cohorts of patients, with mechanistic studies potentially being able to validate the functional consequences of these variants.

Model-Based Quantification of Impact of Genetic Polymorphisms and Co-Medications on Pharmacokinetics of Tamoxifen and Six Metabolites in Breast Cancer

Variations in clinical response to tamoxifen (TAM) may be related to polymorphic cytochromes P450 (CYPs) involved in forming its active metabolite endoxifen (ENDO). We developed a population pharmacokinetic (PopPK) model for tamoxifen and six metabolites to determine clinically relevant factors of ENDO exposure. Concentration-time data for TAM and 6 metabolites come from a prospective, multicenter, 3-year follow-up study of adjuvant TAM (20 mg/day) in patients with breast cancer, with plasma samples drawn every 6 months, and genotypes for 63 genetic polymorphisms (PHACS study, NCT01127295). Concentration data for TAM and 6 metabolites from 928 patients (n = 27,433 concentrations) were analyzed simultaneously with a 7-compartment PopPK model. CYP2D6 phenotype (poor metabolizer (PM), intermediate metabolizer (IM), normal metabolizer (NM), and ultra-rapid metabolizer (UM)), CYP3A4*22, CYP2C19*2, and CYP2B6*6 genotypes, concomitant CYP2D6 inhibitors, age, and body weight had a significant impact on TAM metabolism. Formation of ENDO from N-desmethyltamoxifen was decreased by 84% (relative standard error (RSE) = 14%) in PM patients and by 47% (RSE = 9%) in IM patients and increased in UM patients by 27% (RSE = 12%) compared with NM patients. Dose-adjustment simulations support an increase from 20 mg/day to 40 and 80 mg/day in IM patients and PM patients, respectively, to reach ENDO levels similar to those in NM patients. However, when considering Antiestrogenic Activity Score (AAS), a dose increase to 60 mg/day in PM patients seems sufficient. This PopPK model can be used as a tool to predict ENDO levels or AAS according to the patient's CYP2D6 phenotype for TAM dose adaptation.

Pharmacokinetic and Pharmacogenetic Study of Etoposide in High-Dose Protocol (TI-CE) for Advanced Germ Cell Tumors

BACKGROUND

Etoposide dosing is based on body surface area. We evaluated if further dose individualization would be required for high dose (HD) etoposide within the TI-CE (taxol, ifosfamide, carboplatin, and etoposide) protocol.

METHODS

Eighty-eight patients received 400 mg/m²/day of etoposide as a 1-hour IV infusion on 3 consecutive days over 3 cycles as part of a phase II trial evaluating efficacy of therapeutic drug monitoring (TDM) of carboplatin in the TI-CE HD protocol. Pharmacokinetic (PK) data were analyzed using population PK model on NONMEM to quantify inter- and intra-individual variabilities. Relationship between etoposide exposure and pharmacodynamic (PD) endpoints, and between selected genetic polymorphisms and tumor response or toxicity were evaluated.

RESULTS

The inter-patient, inter- and intra-cycle variabilities of clearance were 16%, 9% and 0.1%, respectively. The PK-PD relationship was not significant despite a trend toward higher etoposide exposure in patients responding to treatment. A significant correlation was found between exposure and extended neutropenia at cycle 3. A significant association between UGT1A1*28 polymorphism and late neutropenia was observed but needs further evaluation.

CONCLUSIONS

The present study suggests that neither a priori dose individualization nor dose adaptation using TDM is required validating body surface area dosing of etoposide in the TI-CE protocol.

[Allergic respiratory diseases related to mould in the home]

Exposure to mould is a potential risk factor for asthma in both adults and children. In adult, the relation between exposure, sensitization and symptoms has been demonstrated in severe asthmatics sensitized to Alternaria. For children, exposure to mould in childhood is a risk factor for asthma in both atopic and non-atopic individuals. Exposure or sensitization to moulds are a risk factor for severe asthma and/or exacerbations in children. There appears to be a causal relationship between exposure and asthma. This link seems less significant in adults. However, in adults mould sensitive asthma seems to determine a phenotype of severe asthma associated with more marked obstructive lung disease. Moulds can stimulate either innate or the acquired immunity. They are responsible for a marked Th2 inflammation leading to more severe asthma. Besides the immunological mechanisms, toxic mechanisms can also intervene. It is therefore not correct to reduce the effect of moulds, particularly in respiratory symptoms, to only allergic mechanisms.

Factors Affecting Tamoxifen Metabolism in Patients With Breast Cancer: Preliminary Results of the French PHACS Study

In addition to the effect of cytochrome P450 (CYP) 2D6 genetic polymorphisms, the metabolism of tamoxifen may be impacted by other factors with possible consequences on therapeutic outcome (efficacy and toxicity). This analysis focused on the pharmacokinetic (PK)-pharmacogenetic evaluation of tamoxifen in 730 patients with adjuvant breast cancer included in a prospective multicenter study. Plasma concentrations of tamoxifen and six major metabolites, the genotype for 63 single-nucleotide polymorphisms, and comedications were obtained 6 months after treatment initiation. Plasma concentrations of endoxifen were significantly associated with CYP2D6 diplotype (P < 0.0001), CYP3A4*22 genotype (P = 0.0003), and concomitant intake of potent CYP2D6 inhibitors (P < 0.001). Comparison of endoxifen levels showed that the CYP2D6 phenotype classification could be improved by grouping intermediate metabolizer (IM)/IM and IM/poor metabolizer diplotype into IM phenotype for future use in tamoxifen therapy optimization. Finally, the multivariable regression analysis showed that formation of tamoxifen metabolites was independently impacted by CYP2D6 diplotype and CYP3A4*22, CYP2C19*2, and CYP2B6*6 genetic polymorphisms.

Inhibiting Integrin β8 to Differentiate and Radiosensitize Glioblastoma-Initiating Cells

Glioblastomas (GB) are malignant brain tumors with poor prognosis despite treatment with surgery and radio/chemotherapy. These tumors are defined by an important cellular heterogeneity and notably contain a subpopulation of GB-initiating cells (GIC), which contribute to tumor aggressiveness, resistance, and recurrence. Some integrins are specifically expressed by GICs and could be actionable targets to improve GB treatment. Here, integrin β8 (ITGB8) was identified as a potential selective target in this highly tumorigenic GIC subpopulation. Using several patient-derived primocultures, it was demonstrated that ITGB8 is overexpressed in GICs compared with their differentiated progeny. Furthermore, ITGB8 is also overexpressed in GB, and its overexpression is correlated with poor prognosis and with the expression of several other classic stem cell markers. Moreover, inhibiting ITGB8 diminished several main GIC characteristics and features, including self-renewal ability, stemness, migration potential, and tumor formation capacity. Blockade of ITGB8 significantly impaired GIC cell viability via apoptosis induction. Finally, the combination of radiotherapy and ITGB8 targeting radiosensitized GICs through postmitotic cell death. IMPLICATIONS: This study identifies ITGB8 as a new selective marker for GICs and as a promising therapeutic target in combination with chemo/radiotherapy for the treatment of highly aggressive brain tumors.

Alpha-6 integrin promotes radioresistance of glioblastoma by modulating DNA damage response and the transcription factor Zeb1

Radiotherapy is the cornerstone of glioblastoma (GBM) standard treatment. However, radioresistance of cancer cells leads to an inevitable recurrence. In the present study, we showed that blocking α6-integrin in cells derived from GBM biopsy specimens cultured as neurospheres, sensitized cells to radiation. In cells downregulated for α6-integrin expression, we observed a decrease in cell survival after irradiation and an increase in radio-induced cell death. We also demonstrated that inhibition of α6-integrin expression affects DNA damage checkpoint and repair. Indeed, we observed a persistence of γ-H2AX staining after IR and the abrogation of the DNA damage-induced G2/M checkpoint, likely through the downregulation of the checkpoint kinase CHK1 and its downstream target Cdc25c. We also showed that α6-integrin contributes to GBM radioresistance by controlling the expression of the transcriptional network ZEB1/OLIG2/SOX2. Finally, the clinical data from TCGA and Rembrandt databases demonstrate that GBM patients with high levels of the five genes signature, including α6-integrin and its targets, CHK1, ZEB1, OLIG2 and SOX2, have a significantly shorter overall survival. Our study suggest that α6-integrin is an attractive therapeutic target to overcome radioresistance of GBM cancer cells.

Place de l’assistance circulatoire dans le choc cardiogénique en France en 2018 : revue de la littérature et perspectives

Le choc cardiogénique reste de nos jours une entité mal définie, assez fréquente en pratique clinique (60 000–70 000 cas/an en Europe), dont le pronostic est sombre, avec une mortalité souvent supérieure à 40 % à 30 jours. À travers cette revue de la littérature, nous essaierons de définir cette entité et ses étiologies, avant de parler de son incidence et de son pronostic. L’approche physiopathologique du choc cardiogénique nous permettra par la suite d’approcher sa prise en charge thérapeutique classique (gestion de la volémie, amines inotropes et vasoconstrictives, ventilation) et les limites de cette dernière. Ainsi, nous aborderons les assistances circulatoires et cardiocirculatoires disponibles en France, afin de les envisager au sein d’une stratégie globale de prise en charge du patient en choc cardiogénique. Nous discuterons plus spécifiquement leurs indications ainsi que l’importance du moment d’implantation afin d’optimiser leur efficacité. Enfin, nous évoquerons les assistances actuellement en développement, mais également les nouvelles stratégies thérapeutiques qui pourraient arriver dans les prochaines années.

[Vocal cord dyskinesia and/or asthma]

INTRODUCTION

Vocal cord dyskinesia or vocal cord dysfunction (VCD) is characterized by intermittent abnormal adduction of the vocal cords leading to airflow limitation at the level of the larynx, in the absence of local organic disease. It may occur in isolation or in association with asthma. The pathophysiology is complex and poorly understood. Wheeze, stridor or apparent upper airway obstruction are the most common symptoms. It occurs in a wide age range, more commonly in women, and diagnosis is often delayed and leads to unnecessary treatments (intubation, tracheostomy and high dose steroids).

METHODS

A retrospective study of 15 cases of VCD (8 cases of isolated VCD and 7 cases of VCD with associated asthma) describing the main clinical features and the diagnosis strategy.

RESULTS

Apparent upper airway obstruction, with or without associated asthma, requires an ear nose and throat examination with laryngoscopy to confirm the paradoxical adduction of the vocal cords during an acute episode of dyspnoea or during a provocation test with triggers like exercise or exposure to irritants, and for the purpose of differential diagnosis.

CONCLUSIONS

VCD remains under-appreciated and misdiagnosed, often by mimicking asthma with which it can be associated. A delayed diagnosis by emergency specialists, pulmonologists and ear nose and throat surgeons leads to unnecessary treatments and morbidity before specific therapy can be given.

3-month prognostic impact of severe acute renal failure under veno-venous ECMO support: Importance of time of onset

PURPOSE

Veno-venous ECMO is increasingly used for the management of refractory ARDS. In this context, acute kidney injury (AKI) is a major and frequent complication, often associated with poor outcome. We aimed to identify characteristics associated with severe renal failure (Kidney Disease Improving Global Outcome (KDIGO) 3) and its impact on 3-month outcome.

METHODS

Between May 2009 and April 2016, 60 adult patients requiring VV-ECMO in our University Hospital were prospectively included.

RESULTS

AKI occurrence was frequent (75%; n=45), 51% of patients (n=31) developed KDIGO 3 - predominantly prior to ECMO insertion - and renal replacement therapy was required in 43% (n=26) of cases. KDIGO 3 was associated with a lower mechanical ventilation weaning rate (24% vs 68% for patients with no AKI or other stages of AKI; p<0.001) and a higher 90-day mortality rate (72% vs 32%, p=0.002). Multivariate logistic regression suggested that KDIGO 3 occurrence prior to ECMO insertion, as well as PaCO2>57mmHg and mSOFA>12 were independent risks factors for 90-day mortality.

CONCLUSION

KDIGO 3 AKI occurrence is correlated with the severity of patients' clinical condition prior to ECMO insertion and is negatively associated with 90-day survival.

Targeting progastrin enhances radiosensitization of colorectal cancer cells

A high percentage of advanced rectal cancers are resistant to radiation. Therefore, increasing the efficacy of radiotherapy by targeting factors involved in radioresistance seems to be an attractive strategy. Here we demonstrated that the pro-hormone progastrin (PG), known to be over-expressed in CRC, and recognized as a pro-oncogenic factor, is a radioresistance factor that can be targeted to sensitize resistant rectal cancers to radiations. First, we observed an increase in PG mRNA expression under irradiation. Our results also demonstrated that down-regulating PG mRNA expression using a shRNA strategy, significantly increases the sensitivity to irradiation (IR) in a clonogenic assay of different colorectal cancer cell lines. We also showed that the combination of PG gene down-regulation and IR strongly inhibits tumours progression in vivo. Then, we demonstrated that targeting PG gene radiosensitizes cancer cells by increasing radio-induced apoptosis shown by an increase in annexin V positive cells, caspases activation and PARP cleavage. We also observed the up-regulation of the pro-apoptotic pathway, JNK and the induction of the expression of pro-apoptotic factors such as BIM. In addition, we demonstrated in this study that inhibition of PG gene expression enhances radiation-induced DNA damage. Our data also suggest that, in addition to increase radio-induced apoptosis, targeting PG gene also leads to the inhibition of the survival pathways, AKT and ERK induced by IR. Taken together, our results highlight the role of PG in radioresistance and provide a preclinical proof of concept that PG represents an attractive target for sensitizing resistant rectal tumours to irradiation. .

FGFR1 Induces Glioblastoma Radioresistance through the PLCγ/Hif1α Pathway

FGF2 signaling in glioblastoma induces resistance to radiotherapy, so targeting FGF2/FGFR pathways might offer a rational strategy for tumor radiosensitization. To investigate this possibility, we evaluated a specific role for FGFR1 in glioblastoma radioresistance as modeled by U87 and LN18 glioblastomas in mouse xenograft models. Silencing FGFR1 decreased radioresistance in a manner associated with radiation-induced centrosome overduplication and mitotic cell death. Inhibiting PLCγ (PLCG1), a downstream effector signaling molecule for FGFR1, was sufficient to produce similar effects, arguing that PLCγ is an essential mediator of FGFR1-induced radioresistance. FGFR1 silencing also reduced expression of HIF1α, which in addition to its roles in hypoxic responses exerts an independent effect on radioresistance. Finally, FGFR1 silencing delayed the growth of irradiated tumor xenografts, in a manner that was associated with reduced HIF1α levels but not blood vessel alterations. Taken together, our results offer a preclinical proof of concept that FGFR1 targeting can degrade radioresistance in glioblastoma, a widespread problem in this tumor, prompting clinical investigations of the use of FGFR1 inhibitors for radiosensitization. Cancer Res; 76(10); 3036-44. ©2016 AACR.